U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Ndubuisi George Orji (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 126 - 150 of 155

Nano- and Atomic-Scale Length Metrology

January 1, 2006
Author(s)
Theodore V. Vorburger, Ronald G. Dixson, Joseph Fu, Ndubuisi George Orji, Shaw C. Feng, Michael W. Cresswell, Richard A. Allen, William F. Guthrie, Wei Chu
We discuss nano-scale length metrology of linewidth, step height, and line edge roughness (LER). These properties are of growing importance to the function and specification of semiconductor devices as the dimensions of semiconductor devices shrink to the

Line Edge Roughness Metrology Using Atomic Force Microscopes

January 1, 2005
Author(s)
Ndubuisi G. Orji, Theodore V. Vorburger, Joseph Fu, Ronald G. Dixson, C Nguyen, Jayaraman Raja
Line edge roughness measurements using two types of atomic force microscopes and two types of tips are compared. Measurements were made on specially prepared samples with inscribed edge roughness of different amplitudes and wavelengths. The spatial

Linewidth Measurement from a Stitched AFM Image

January 1, 2005
Author(s)
Joseph Fu, Ronald G. Dixson, Ndubuisi G. Orji, Theodore V. Vorburger, C Nguyen
Image stitching is a technique that combines two or more images to form one composite image, which provides a field of view that the originals cannot. It has been widely used in photography, medical imaging, and computer vision and graphics. For such

Traceable Pico-Meter Level Step Height Metrology

December 1, 2004
Author(s)
Ndubuisi G. Orji, Ronald G. Dixson, Joseph Fu, Theodore V. Vorburger
The atomic force microscope (AFM) increasingly being used as a metrology tool in the semiconductor industry where the features measured are at the nanometer level and continue to decrease. Usually the height sensors of the AFM are calibrated using step

Determination of Optimal Parameters for CD-SEM Measurement of Line Edge Roughness

May 1, 2004
Author(s)
B Bunday, M R. Bishop, D Mccormack, John S. Villarrubia, Andras Vladar, Theodore V. Vorburger, Ndubuisi George Orji, J Allgair
The measurement of line-edge roughness (LER) has recently become a topic of concern in the litho-metrology community and the semiconductor industry as a whole. The Advanced Metrology Advisory Group (AMAG), a council composed of the chief metrologists from

Space-Scale Analysis of Line Edge Roughness on 193 nm Lithography Test Structures

October 1, 2003
Author(s)
Ndubuisi G. Orji, Jayaraman Raja, Theodore V. Vorburger, Xiaohong Gu
Line edge roughness (LER) is a potential showstopper for the semiconductor industry. As the width of patterned line structures decreases, LER is becoming a non-negligible contributor to resist critical dimension (CD) variation. The International Technology

Influence of analysis Algorithms on the Value of Distorted Step Height Data

September 1, 2003
Author(s)
Ndubuisi G. Orji, Jayaraman Raja, Son H. Bui, Theodore V. Vorburger
One of the most important aspects of step height evaluation are the analysis algorithms used. There algorithms assume that the profiles and images being analyzed are ideal, but real step profiles are not ideal and the analysis algorithms can influence the

Sub-Nanometer Wavelength Metrology of Lithographically Prepared Structures: A Comparison of Neutron and X-Ray Scattering

June 1, 2003
Author(s)
Ronald L. Jones, T Hu, Eric K. Lin, Wen-Li Wu, D M. Casa, Ndubuisi George Orji, Theodore V. Vorburger, P J. Bolton, Z Barclay
The challenges facing current metrologies based on SEM, AFM, and light scatterometry for technology nodes of 157 nm imaging and beyond suggest that the development of new metrologies capable of routine measurement in this regime are required. We provide

Scale-Space Analysis of Line Edge Roughness on 193 nm Lithography Test Structures

January 1, 2003
Author(s)
Ndubuisi G. Orji, Theodore V. Vorburger, Xiaohong Gu, Jayaraman Raja
Line edge roughness (LER) is a potential showstopper for the semiconductor industry. As the width of patterned line structures decreases, LER is becoming a non-negligible contributor to resist critical dimension (CD) variation. The International Technology

Surface Finish and Sub-Surface Metrology

January 1, 2003
Author(s)
Theodore V. Vorburger, Ndubuisi George Orji, Li Piin Sung, T Rodriguez
Surface finsih affects the performance of a wide variety of manufactured products ranging from road surfaces and ships to mechanical parts, microelectronics, and optics. Accordingly roughness values can vary over many orders of magnitude. A variety of

Surface Metrology Software Variability in Two-Dimensional Measurements

January 1, 2003
Author(s)
Ndubuisi G. Orji, Theodore V. Vorburger, Xiaohong Gu, Jayaraman Raja
A range of surface texture measurement instruments is available in the market place. Most of the measurement instruments are microcomputer-based systems that contain their own surface analysis software to evaluate measured roughness profiles. After a